These brackets are installed between the top shock mount and the outer bolt, or on the inside between the shock and the frame.
The small hole is 10mm and takes the standard 10mm (or smaller) turn signal mounting bolt.
The large hole is 16mm, which will also fit many custom applications. CNC machined from 3mm aviation grade billet 6061 T6 aluminum.

Fits: > Triumph: 01-18 Bonneville T100 / SE / Scrambler / Truxton / Street Cup / T120 (Carb en EFI models) and custom applications